Electric discharge device



Feb. 9, 1932. I c A SABBAH TAL ELECTRIC DI SCHARGE DEVIC E Filed Jan. 28, 1930 IYIVQTTLOTSZ Cami! A. Sabbah,

Carl C. HersKirwd;

Their" Attorneg,

Patented Feb. 9, 1932 iJNITED STATES PATENT OFFICE GAMIL A. SABBAH AND CARL C. HERSKIND, OF SCHENEC'IADY, NEW YORK, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK ELECTRIC DISCHARGE DEVICE Application filed January 28, 1930. Serial No. 424,045,

Our invention relates to electric discharge devices, such as mercury arc rectifiers and the like, and has for its principal object the provision of an improved apparatus and method of operation whereby the operation of such devices is readily initiated.

In various types of electric discharge devices, a starting electrode provided for producing a small arc whereby operation of the device is started. Different types of devices have been provided for producing this starting arc. Many of these devices are not altogether satisfactory for the reason that they involve movement of the evacuated vessel or require that movement be communicated to the starting electrode through the vessel wall. In accordance with our invention, these difficulties are avoided by the provision of a magnetic element which is mounted within the evacuated vessel.

Our invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in 2 the appended claims.

The drawing illustrates a mercury rectifier arc device wherein our invention has been embodied. This device includes an evacuated vessel 10 within which are mounted a cathode 11, a pair of anodes 12 and a starting electrode 13. Interposed between the starting or auxiliary electrode 13 and the lead 14 through which current is supplied to this electrode, is an electromagnetic de- 3 vice including a magnetic core 15 and a spiral spring winding 16 of magnetic material which supports the electrode 13.

The operation of the starting apparatus will be readily understood if it is assumed that the starting electrode 13 is in its illustrated position when no current is supplied to it through the lead 14. Under these conditions the spring winding 16 is extended so that the starting electrode is in contact with the cathode 11. When current is supplied to the winding 16 through the lead 14, the magnetic force due to this current causes the spiral winding to contract, thus disengaging the electrode 13 from the cathode 11 and producing a starting are which is readily communicated to the anodes 12 in a manner well understood by those skilled in the art. As long as the starting are between the electrode 13 and the cathode 11 is maintained, the spiral winding remains contracted. In case the arc goes out, it is automatically restarted.

It will be apparent that our improved arrangement has the great advantage that the starting apparatus is located altogether within the evacuated vessel so that no movement of the vessel and no communication of motion through the wall of the vessel is required to start the arc. While the core 15 has been illustrated as conical in shape, it will be apperent that it is not limited to this particular structure, and that solenoids of different forms may be utilized without departing from the spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electric discharge device including an evacuated vessel, main and auxiliary electrodes mounted within said vessel, a conical magnetic core mounted within said vessel, and a winding arranged adjacent the surface of said conical core and connected in series with said auxiliary electrode for causing said auxiliary electrode to engage and disengage one of said main electrodes.

2. An electric discharge device including an evacuated vessel, main and auxiliary electrodes mounted within said vessel, a conical magnetic core mounted within said vessel, and a resilient winding supported by said core adjacent the lower surface thereof and connected in series with said auxiliary electrode, the arrangement being such that said auxiliary electrode is in contact with one of said main electrodes when said Winding is deenergized and out of contact with said main electrode when said winding is energized.

3. An electric discharge device including an evacuated vessel, main and auxiliary electrodes mounted within said vessel, a magnetic core mounted within said vessel and having a cone-shaped lower surface, a resilient Winding supported by said core adja cent said surface and arranged to be extended when said auxiliary electrode is deenergized, and to be contracted When said auxiliary electrode is energized.

In Witness whereof, We have hereunto set our hands this 27th day of January, 1930. CAMIL A. SABBAH. CARL C. HERSKIND. 

